5c1, 5c3, 5f1, 5e3 concurrent builds

Discussion in 'Shock Brother's DIY Amps' started by motor_city_tele, Jul 2, 2012.

  1. hackworth1

    hackworth1 Friend of Leo's Vendor Member

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    Not really, but it helps.

    If the socket pins are tight, the tube will stay in, but with a shield, it can't vibrate loose.

    There are a two main types of 9 pin sockets. One has a base which permits the addition of a shield which screws onto bayonet pins.

    There is a spring inside the shield which provides tension against the base so that everything is snug.

    The other is a flat style which does not faciliate a screw on shield.

    The other use for a shield is to block RF interference and to help prevent microphonics.
     
  2. Glen Smith

    Glen Smith RIP

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    Thanks Dave.
     
  3. motor_city_tele

    motor_city_tele Tele-Afflicted

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    A couple of templates

    It's already june and I haven't done a lick of amp work (or guitar work) since the snow melted. I did purchase a brake and experimented with some thin steel. I also located a huge sheet of military grade aluminum that showed up while organizing the folks garage. I will be bending up a few deluxe chassis out of this sheet of aluminum. for those interested, i made up a couple simple templates that I will be using for hole and bend references. You can print them 100% on 11x17 stock.

    [​IMG]

    [​IMG]
     
  4. motor_city_tele

    motor_city_tele Tele-Afflicted

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    Hi folks - Did I miss anything?

    Now that the guitar building challenge thingy is over, I can get back to my amps. Last week I managed to get one of my 5E3's in the hands of a decent player. Here is how it sounds.



    I never did get to apply any of the shellac I bought. It's still unopened. But so what, If the cab gets a little rumpled or scuffed It makes no difference one way or the other. It's all about the sound.

    tootles - jb
     
  5. motor_city_tele

    motor_city_tele Tele-Afflicted

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    Power Transformer Selection for 5C3

    I am going to finally get the 5C3 finished soon. I ended up bending the chassis wrong back a few months (years) ago and just stopped. Well I've dug out my box of old trannies and these three seemed to fit the bill. Originally, I planned on using the Crest NOS tranny like I did with three other deluxe amps (5E3).
    Even though I have three, no single tranny is a perfect match. the top would need an artificial CT, the middle has a 5 volt CT, and the bottom might be under powered. but then again, the 70ma trannies power my other tweeds just fine.
    The hole patterns are slightly different so I would have to choose before drilling the opening in my chassis.

    I will be using 1) 5Y3, 2) 6V6, 2) 6SL7 tubes

    340-0-340V @110MA, 5V @3A, 6.3V @2.5A <--- no 6.3 CT

    350-0-350V @90MA, 5VCT @3A, 6.3VCT @3.5A <--- extra 5 volt CT

    350-0-350V @70MA, 5V @3A, 6.3VCT @3.5A <--- Crest

    any suggestions would be appreciated.

    tootles - jb
     
  6. robrob

    robrob Poster Extraordinaire Ad Free Member

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    You can shrink tube that 5v center tap and use it for a rectifier.

    The 340-0-340v would be closest to what the 5C3 needs and an elevated artificial center tap on a power tube socket can be quieter than a true center tap so that's what I'd recommend.
     
  7. motor_city_tele

    motor_city_tele Tele-Afflicted

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    5C3 Chassis - take two

    Ever since I folded the chassis backwards on my 5c3, I've not done a thing with it. So I printed the 11 x 17 template from a few posts back and adhered it directly to the new piece of sheet metal. Then I marked my holes, gave them a starter punch and drilled them all out. I folded up the box in my sheet metal brake. Harbor Freight el-cheapo 18 inch brake does ok.

    I bolted in the sides on and started adding the parts.
    [​IMG]

    340-0-340 @110ma PT from Gary. This one does not have 6.3 volt center taps so I will have to apply an artificial center tap. robrob has good examples available on his ad free website.
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    Switches and power tranny stuff on the left.
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    Switches needed to be moved because they ran into the PT bell. No big deal.
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    1 1/8 inch octal holes drilled
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    The 95 cent parts express sockets look fine. I wonder how they function. Note to self - check these first when sommat starts acting up. recto and 6v6 sockets bolted in.
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    6SL7 sockets installed.
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    Inputs and pots from the inside.
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    Inputs and pots from the top.
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    The board gets tossed in and . . . now the real fun begins.
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    I'll probably get this thing put together and working this weekend. I'll then take it apart and do some sort of finish on the chassis. I really would like to successfully get some paint and lettering applied so I can have a process to finish all of the other hand made chassis' I have hanging around.
     
    Last edited: Jul 16, 2015
  8. robrob

    robrob Poster Extraordinaire Ad Free Member

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    Your chassis and build look good. Nice metal working.
     
  9. motor_city_tele

    motor_city_tele Tele-Afflicted

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    Wiring up the 5C3

    strain relief installed
    [​IMG]

    Then the other end
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    OT mounted
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    I like to hook up the power, pots, inputs, bus, then tubes from left to right.
    [​IMG]

    pots then inputs
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    I used a strip of brass for my omnibus
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    now flip it over and wire the recto and two power tube sockets.
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    The artificial CT gets installed on V3. 100 ohm across each filament lug and pin 8 (cathode)
    [​IMG]

    Then wire the sockets for the two 6SL7's
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    inside top
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    inside bottom
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    I hooked it up to an existing cab, plugged it in an fired it up. - seems to be working fine. no buzzing, no hum, no smoke, tubes heating up.
    [​IMG]

    I played an esquire for a few minutes on all 4 inputs - sounds fine.

    I took some measurements.
    B+ 354 volts
    node two - 281 volts
    node three - 257 volts

    V1 - Triode plate one - 70 volts
    V1 - Triode plate two - 75 volts

    V2 - Triode plate one 133 volts
    V2 - Triode plate two - 130 volts

    V3 plate - 327 volts
    V3 screen - 279 volts
    V3 cathode - 16 volts

    V4 plate - 354 volts
    V4 screen - 279 volts
    V4 cathode - 16 volts

    I think I need to assemble a few more of the deluxe cabs.
     
  10. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    So many skills! I love the real DIY in your projects. Thanks for getting back to this one.
     
  11. motor_city_tele

    motor_city_tele Tele-Afflicted

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    dug up a cab for my 5C3

    After taking the shop Vac to it. I broke out the amber shellac and lacquer.
    I ended up brushing 2 coats of shellac and 4 coats of clear Deft.
    [​IMG]

    While it dried in the 90 degree heat I thought I'd pull out the baffle and mount the speaker
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    I purchased the 12 inch speakers a few years ago. I bought 4 of these for 35.00 each.
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    Screwed into the baffle.
    [​IMG]

    After it dried, I pretty much assembled it up.
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    The last (other than painting the chassis) thing to do is to stick on my chrome label.
    [​IMG]

    The amber is pretty dark. I may not brush it on next time. I'll spray it on through a gun using my compressor.
    [​IMG]


    I plugged my newest guitar into the amp and played for a little bit, I like this amp. Quite as can be, very little hum. The breakup is just about right. I'm debating whether or not I'm gonna bash up the finish fabric and give it a worn look.
    [​IMG]
     
    Last edited: Jul 20, 2015
  12. cap47

    cap47 Tele-Holic

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    I wouldn't, leave as is and the darker shellac looks fine makes it look like some of the old amps my father had in the 50s. I wouldn't mind mine looking that dark!
     
  13. motor_city_tele

    motor_city_tele Tele-Afflicted

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    What is STANDBY

    Before I finish this 5c3 chassis faceplate, I need to know exactly what this standby label means. On the pre-printed chassis I've seen the STANDBY label is below the switch on the same line as ON switch. The OFF label is above the switch.

    With both switches down, both switches are on.

    with STANDBY switch up and main down amp is on but ????
    with STANDBY switch down and main switch OFF what happens when main is switched on???

    I've read threads where this switch is bypassed which means that leaving it on would be the same thing. I'm sure it had a function at one point.
     
  14. robrob

    robrob Poster Extraordinaire Ad Free Member

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    With both switches down, both switches are on: true

    with STANDBY switch up and main down: No DC flows to the amp, only AC to rectifier and tube heaters.

    with STANDBY switch down and main switch OFF what happens when main is switched on: Rectifier tube is fully powered and warms up and the tube heaters are powered to get the amp ready to run but there's no DC yet.

    If an amp has a STBY switch I like to bypass it with a 100k to 220K resistor to allow the filter caps to slowly charge--I always power up the amp with the STBY switch open so the caps slowly charge while the tube heaters warm up. About 15 seconds it all the delay that's required between powering up and closing the STBY switch.

    But, and this is a big but, the STBY switch is not needed so feel free to leave it out.
     
  15. Preacher

    Preacher Friend of Leo's

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    Don't know how I missed this thread but I read this and had to comment.
    Our RS recently closed, and although there was not one person in there who knew what in the world I needed, they at least had some parts in a pinch. I agree, if something ever happens there are going to be very few people who know how to make anything anymore...
    As long as our future stays the course of no interpersonal contact, viewing screens, and computers and robots we will be fine. If something happens and we have to actually build and think for ourselves from what we have on hand we are in big trouble!
     
  16. motor_city_tele

    motor_city_tele Tele-Afflicted

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    Letraset rub off letters off ebay.
    [​IMG]

    My thoughts on the faceplate.
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    Masked the chassis with clear tape and gave it some steel wool. Then I sprayed a few coats of lacquer.
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    Added the letters. I decided to omit the action part of the label and just kept the source. I also abbreviated the Bright and Normal inputs. These letters are hard to rub onto the chassis. I'm a bit out of practice. It's been 30+ years since I've used these. Well, It's good enough for me. I sprayed the clear over the letters to fix them into place.
    [​IMG]

    Normal seems to be a bit abnormal if you ask me.
    [​IMG]

    Peeled off the tape and cleaned up the holes.
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    Buttoned it back up.
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    This process would will work fine. I just need to take my time next amp.
    [​IMG]

    Total time from start to finish about three hours, and that included a trip to ACE for a can of clear.
    [​IMG]
     
  17. motor_city_tele

    motor_city_tele Tele-Afflicted

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    An early peek at this years jack-o-lantern
    [​IMG]
    I will do another one tomorrow after the Lions game.

    see you in a day or two
     
    tubeswell likes this.
  18. tubeswell

    tubeswell Friend of Leo's

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    ^Far out!^
     
  19. robrob

    robrob Poster Extraordinaire Ad Free Member

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    Did you add the 1M input resistors to the two high inputs after this pic? They act as the V1 grid leaks and set the amp's input impedance.

    [​IMG]
     
  20. motor_city_tele

    motor_city_tele Tele-Afflicted

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    Rob,

    I did not alter the above board after I soldered the components. I just used the weber 5c3 layout as is.

    As promised, this year's model

    [​IMG] [​IMG] [​IMG]
     
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